Nackles

Nackles is an alternate name of Europe's Black Peter. (I don't think the Grateful Dead song is a reference.) He is also known by other names in Europe, such as Hans Trapp, Knecht Ruppert, Krampus, and Swart Peter.

Whereas the American Santa Claus both rewards good kids and—in theory if not common practice—punishes bad ones, in parts of continental Europe, the punishment and reward functions are divided amongst two figures. St. Nicholas is the kindly saint who wears red and brings the good children presents. Nackles is an evil figure robed in black robes (an ancient political criticism has Peter sporting Spanish clothes) who lives underground in a coal mine. He keeps an eye out for the truly bad children, and on Christmas eve he launches from his tunnels on a coal-cart pulled by plague-ridden, skeletal rams. He kidnaps the bad children, putting them in his sack of rats. He takes them back to his mine to be his slaves, where they are forced to dig coal. During this enslavement, Nackles pokes them with pins. One day, the legend goes, he will eat them.

If a child is just naughty—rather than full-blown wicked—and in danger of being taken, Nackles leaves a lump of coal in their Christmas stocking as a warning of the fate to befall them next year.

Harlan Ellison wrote a screenplay of the short story for The Twilight Zone in 1985 called "The Deadly Nackles Affair" which in his own words raised issues of bigotry and racism, but network executives canceled the show at the absolute last minute, fearing it was too dark for the fragile American market.